Have heard different opinions on effects of bullet run-out on accuracy in hunting rifles. I've started to put some loads together using my oldest die, one that came with my press in 1973: a RCBS FL sizer. The bullet run-out is consistently .010-.012". I'm putting these loads together and loaning my rifle to an old friend, so don't really want to buy any other equipment to tune the cases up. So my question, based on your experiences with bullet run-out on seated bullets in a HUNTING rifle, in this case a .30-06 Model 70, is that much run-out alone, going to make a difference in accuracy?

Thats a lot of run out.
How do they shoot?
How do you check runout?
using old brass or new brass.
FL resize all my hunting runout is what ever I end up with usually under .005". I have some that were around .007. They all kill deer.
check and see how much run out you have with the neck. then check the bullet run out.
The neck will be thicker in one spot. that the nature of the brass. My target loads are kept to as close to 0 as possible.
i use Lee collet dies for neck sizing the collet die squeezes the brass around a mandrel. helps keep it straight

These days I don't bother checking bullet run-out. Mainly because I seat with Redding Competition Micrometer Seaters which keep run-out tight enough for my needs.
In reply to your question, based on times when I measured run-out, I would expect your run-out to have some effect on accuracy. However, the load / rifle combination may still shoot accurately, or accurately enough, despite this. Shoot it first and see. If accuracy is acceptable, no problem.
I'm talking about hunting rifles here BTW.
Run-out iteslf is not an absolute. I remember one time I worked up 30.06 loads, got run-out to very minimal measurements and was disappointed with accuracy. For comparison I bought some Norma ammo, different bullet but same bullet weight, measured run-out first which was much more variable than mine, and the ammo shot very tight groups. Just goes to show you...

I'm using a Sinclair Concentricity Gauge. Neck run-out of FL sized cases is running .007-8 average and then it jumps up another .002-.005" after bullet seating. I've just started load development so haven't shot that many groups. Shooting 3 shot groups and they vary quite a bit: from 1 1/4" to 2+ mostly. I shoot quite a number of other calibers and mostly use Sinclair neck expander dies which keep run-out really low. Like I said, this is for a friend and just for one hunt, so really don't want to buy another die. However, if the concensus is that that much run-out is die related, then I'd do it anyway. Like I said: dies are 1973 vintage and I suspect that tolerances back then were pretty wide.

I agree that’s quite a bit of run out…

But 2” at 100 is usable hunting accuracy for the most part.

So, yes it quite a bit, yes, I expect better dies would reduce it, yes, I think you could get smaller groups with tighter tolerance equipment…

But I’m not sure it’s really worth the squeeze for a 1 and done hunt. It might well be cheaper for a box of factory ammo, for that matter.

What’s the quarry? Whitetail/pronghorn I’d say good enough. Mountain sheep I’d be trying to tighten it up more.

quote:

I'm using a Sinclair Concentricity Gauge. Neck run-out of FL sized cases is running .007-8 average and then it jumps up another .002-.005" after bullet seating.

Try rotating the brass 180* and resize a couple time. That might straighten the neck up make sure you lube the inside of the necks pretty good the expander may be pulling the neck to one side. make sure you have a good inside neck champer

Concur with using an expander die (either Sinclair or Wilson . . . or if you want really fine neck tension control, the 21st Century die). Unfortunately, standard FL Sizing dies that use an expander ball generally apply offset torque as the ball moves upward through the neck. This issue is solved by using a neck bushing die, or by removing the FL die expander ball entirely and using the separate expander die to size the neck. As an added bonus, the mandrel on expander dies results in a much more reasonable (less) neck tension around .002 (exact measurement depends on annealing, etc.) - many FL Sizing dies result in far too much neck tension.

Regards,

You won't notice any difference on an old 30-06 hunting rifle.

so Tom, now I'm curious: which kind of rifles WOULD such run-out have an effect on? new vs. old rifles, smaller caliber rifles, varmint rifles primarily, custom rifles, etc?

Varmint calibers, bench rest, some target rifles.
Average hunters; especially ones with worn throats; no. If the throat is sloppy or worn, the straight bullet will immediately become canted; however, once it hits the bore it will be straight enough for the usual hunter.
Read what 30-06 said above.

Not a hunting rifle, but anyway.

Here is a test of accuracy at 1000 yards with deliberately-mis-aligned bullets.

https://www.youtube.com/watch?v=6m8Y6ZmSBiU

From various faffing around, I have become fairly convinced that case condition may have more effect on bullet runout than the seating die.

Good brass, uniformly annealed and correctly sized.